Requested feature overview description.
Bring back the old feature of setting a tag's category by using the category as preffix, but only when creating new tags.
Why would it be useful?
I understand this feature was removed because of abuse, but that's not possible if it's limited to a tag which is being created. It saves some time for whoever creates a new tag and has no downsides.
What part(s) of the site page(s) are affected?
Any page in which tags can be added to a post.